In recent years, three-dimensional computer graphics (3DCG) is used in various fields. A user can generate 3DCG in a virtual space and appreciate the virtual space from an arbitrary viewpoint by operating a 3DCG application. In this case, the user is required to perform complicated operations, such as identifying a position in the virtual space with three coordinates of X coordinate, Y coordinate, and Z coordinate, and designating various parameters. Therefore, such a technology is developed that improves an operational environment of the 3DCG application.
For example, in the following Patent Literature 1, such a technology is disclosed that determines the position of a viewpoint defined in the virtual space according to the posture of a device in a real space.